1. Field of the Invention
The present invention relates to a method of molding man-made boards to produce contoured furniture parts. More particularly, the present invention relates to a method of molding a man-made board to produce contoured furniture or decorative parts, such as a drawer front, cabinet door, table top, and the like. A fiberboard or particle board blank is first formed and cut to a size slightly larger than interior dimensions of a mold. The cut blank can be pre-treated with a sealer, preferably including a release agent, and is then molded at a temperature of at least 200.degree. F. to form the blank into its final shape.
The process of the present invention relates to a "post-press" or after consolidation molding operation for molding a fiberboard or particle board into a furniture part or decorative part having a desired shape. The fiberboard or particle board substrate is formed by depositing a mass of fibers onto a support member, by either a dry deposition process or wet deposition process known in the art of papermaking or fiberboard manufacture, and then consolidating the fibers by drying or under test and pressure. Typical products made by these processes are insulation board, medium density fiberboard and particle board.
The consolidated mat is first manufactured by consolidating a cellulosic fiber-containing composition to form a consolidated fiberboard or particle board. The consolidated mat can be consolidated by drying a mat formed by depositing a water slurry of fibers onto a water pervious support member, as is common in the manufacture of insulation board, or the mat can be consolidated under heat and pressure until substantially dry in a first press operation. The consolidated mat is thereafter "post-pressed" in a mold having the desired configuration to form the consolidated fiberboard into a desired shape and to impart surface texture if desired.
After board consolidation, the blank is cut from the board to a size slightly larger than interior dimensions of a mold cavity. The consolidated cut blank is thereafter "post-press molded" in a mold having a desired internal configuration to mold the consolidated fiberboard blank into a multi-sided part having a desired shape and to form a surface design corresponding to natural wood or other decorative materials, such as cork, slate and the like. For the purpose of the present invention, a "post-press molding" operation refers to a molding step performed on a consolidated man-made board which changes the dimensions of the consolidated board in all three of its dimensions.
The fiberboard of the present invention is generally formed in two separate operations. The first operation forms a consolidated man-made board of any desired density, i.e, 10-65 pounds/ft..sup.3, in a manner common in the art of forming a fiberboard, such as insulation board or medium density hardboard. The second step comprises "post-press molding" which changes the overall dimensions of the consolidated fiberboard along its length, width and height to form a multi-sided contoured board having dimensions corresponding to the dimensions of the mold cavity. It is quite surprising that a "post-press molding" operation is effective in substantially altering the dimensions of a consolidated fiberboard in all three dimensions to produce a multi-sided embossed part without visible fiber tearing or delamination.
2. Description of the Prior Art
It is very difficult to both densify and restructure the surface of a consolidated fiberboard without destroying the fiber-to-fiber surface welds referred to in this assignee's U.S. Pat. No. 4,007,076 and co-pending application Ser. No. 739,184 filed Nov. 5, 1976, now U.S. Pat. No. 4,175,150.
An article entitled "Wood Embossing Machines Cut Product Steps For `Carved` Parts" by Bruce Scully, appearing in Furniture Design & Manufacturing, February, 1977, pages 30-33 and an article entitled "Two New Concepts in Embossing" by Darrell Ward, appearing in Woodworking & Furniture Digest, June, 1977, pages 46-50, relate to embossing materials, including fiberboard, in making furniture parts, but do not suggest molding a man-made board to produce multi-sided furniture or decorative parts as disclosed herein.